The present invention relates to an injection nozzle, and more particularly, to a nozzle for the injection of foam insulation comprising a mixture of foaming agent and a hardening resin.
The injection of foam insulation into buildings has in the past been largely an art by which the operator must carefully adjust the flow rate of pressurized air, foaming agent and liquid resin into prior art nozzles which are then inserted into apertures between the wall spaces of a building for the injection of the liquid foam insulation which subsequently hardens. U.S. Pat. No. 3,186,959 issued June 1, 1965 to D. S. Shriver et al. and U.S. Pat. No. 2,992,194 issued July 11, 1961 to H. C. Paulsen are representative of prior art systems for such injection. In other commercially used foam injection nozzles, a beaded chamber is employed by which a mixture of air and foaming agent passes in order to cause the desired foaming of the liquid foaming agent before mixture with the hardening resin.
A common problem with prior art nozzles of this construction is that the foaming chamber can become relatively easily clogged thereby disabling the nozzle. Also the expanded foaming agent and liquid resin hardener are mixed within the nozzle body which also frequently clogs requiring disassembly of the nozzle before it can again be used. These problems cause significant difficulties at the job site where the operator frequently must repeatedly disassemble the nozzle and attempt to clear the blockage before proceeding with the installation of the foam insulation. The problem becomes particularly acute to the operator in cold or other inclement weather encountered by the operators.